August weenicke



5o perature of about 106 to 110 centigrade. calcium, either of which hasto be employed I00 7 UNITED STATES PATENT OFFICE.

AUGUST WERNIOKE, or HALLE-ON-THE-SAALE, AND WILHELM PFITZINGER OFSTANCE, PRUSSIA, GERMANY.

METHOD OF EXTRACTING CRYSTALLIZABLE SUGAR FROM MOLASSES, dc.

SPECIFICATION forming part of Letters Patent No. 260,340, dated June 27,1882,

Application filed May 23, 1882. (No specimens.)

To all whom it may concern:

Be it known that we, AUGUST WERNICKE, of Halle-on-the-Saale, Prussia,Germany, engineer, and WILHELM PFITZINGER, of Stanch, Prussia, Germany,temporarily residing at Prague, Austria, chemist, have invented anImproved Method of Obtaining Grystallizable Sugar from Raw Sugar,Saccharine Juices, Sirup, and Molasses, of which the following is aspecification.

The method of obtaining crystal'lizable sugar which forms thesubject-matter of the present invention is based on the property ofacetic acid of being a solvent of all foreign matter contained in rawsugar, in saccharine juices, in sirup, and in molasses, whilecrystallizable sugar is absolutely insoluble therein.

In order to obtain crystallizable sugar from raw sugar, it isadvantageous, first of all, to free the latter from the greater part ofthe water which it contains by a drying process carried out withapplication of heat. After having been cooled to below 70 centigrade thesugar is intimately mixed with from fifty to seventy per cent., or'thereabout, of its weight of concentrated acetic acid, the mixing beingcarried out in a closed receptacle having by preference the form of ahorizontal cylinder, and provided with a stirring apparatus. The mixtureis thereupon drawn off and allowed to remain at rest and to cool inother vessels fitted with covers, and which may have a capacity of eightcubic feet. After a certain time-say from thirty-six to fortyeighthours--nearly all sugar has separated or crystallized out in pure state,while the motherlye consists in the acetic acid containing, in solution,all the foreign substances with but traces of sugarr The bulk of thisliquid having been drained off from the sugar, the rest is extracted ona centrifugal drying-machine or in any other known manner. If it shouldbe required, the sugar is comminuted before it is brought into the saidmachine. In order to complete its purification of adhering lye, thesugar is washed on the machine with some pure acetic acid, whereupon itis dried in a closed iron cylinder provided with a stirring apparatus,and heated by steam to a tem- For the purposeof recovering the aceticacid which is evaporated from the sugar, the vapors are conducted into acondensing-Worm. Instead of washing out the sugar on the centrifugalmachine by means of acetic acid, it may also be freed from the residueof motherlye by means of a solution of sugar.

When the sugar contained in saccharine juices, molasses, or sirup is tobe extracted the liquid is concentrated as much as possible z'. 6., tofrom to Baum-by evaporation in vacuum. After having been cooled to belowcentigrade the concentrated acetic acid is added, of which in this casefrom seventy-five to ninety per cent. of the weight of the saccharineliquor is required, according as it is more or less concentrated. Themixing with the acid, which requires but a few minutes of time, is againcarried out in a closed vessel with stirring apparatus; also, thefurther treatment of the liquor and of the sugar separating orcrystallizing out therefrom is substantially the same as hereinbeforedescribed.

In case the raw sugar, the molasses, &c., are not mechanically mixedwith impurities, the sugarobtained by this process is generallysufiiciently white. In the contrarycase it must be subjected to afurther purification by dissolving, filtering, and reconcentrating it.

The acetic acid to be employed must be of a high degree ofconcentration,especially when saccharine liquors, sirup, or molasses areto be treated. In this case it is preferable to use an acid containingfrom ninety-eight to one hundred per cent. of pure acid. For sirups andother saccharine liquors which are evaporated to a density of from 50 to52 Baum, an acid of a strength of ninety per cent. would, how ever, besufficient, and for raw mlgar an acid still somewhatless concentratedmight be used.

In order to recover the acetic acid from the mother-l ye, the latterisdistilled preferably in a still made of cast-iron and provided with acover and a condensing-worm of earthenware. The acid thus obtained issubsequently to be freed from the water which it has taken up from thesugar, molasses, &c. This may be done by means of bisulphate of soda orof chloride of in anhydrous state. If the latter salt is used, it isnecessary to cause the muriatic acid evolved during the process ofdistillation to be absorbed by the medium of dry acetate of 5 soda,which is put into a vessel inserted between the head of the still andthe condenser. If the degree of concentration attained by the aforesaidsalts should not be sufficient, the acid has to be converted by additionof lime into acetate of lime, which, after having been completelydesiccated, is decomposed again by sulphuric acid for the purpose ofliberating the acetic acid, which is then completely concentrated.

1 5 The residue from the distillation of the acetic acid may be utilizedas manure or for producing ammonia, methyl, potash, 85c.

\Ve claim as our invention- The method of obtaining crystallizable or 20crystallized sugar from raw sugar, saccharine juices, sirup, andmolasses by adding concentrated acetic acid to the raw sugar or thesaccharine liquor, allowing the sugar to separate or crystallize out,liberatiu g the sugar from the mother-lye by mechanical means, andfinally 2 5 evaporating the residue of acetic acid or water or of acidand water, substantially as hereinbefore described.

In testimony whereof we have signed our names to this specification inthe presence of 30 two subscribing witnesses.

AUGUST WERNICKE. WILHELM PFITZINGER.

Witnesses for A. Wernicke:

CARL PIEPER, B. R01.

Witnesses for Pfitzinger: CARL RUPPERT, LEO SE RELTs.

